Elastic wave field computation in multilayered nonplanar solid structures: a mesh-free semianalytical approach

Area of Science:

• * Solid mechanics
• * Acoustics
• * Materials science

Background:

• * Multilayered solid structures are crucial in aerospace, mechanical, and civil engineering.
• * Accurate modeling of ultrasonic fields in these structures, especially with finite-size transducers, remains a challenge.
• * Existing paraxial methods like ray tracing and Gaussian beams have significant limitations.

Purpose of the Study:

• * To develop and present a novel semianalytical method for modeling elastic wave fields in multilayered solid structures.
• * To provide a general formulation applicable to both isotropic and anisotropic materials with planar or nonplanar interfaces.
• * To incorporate various interface conditions, including irregularities.

Main Methods:

• * Utilizes a semianalytical approach based on frequency-domain displacement and stress Green's functions.
• * Employs different elastodynamic Green's functions for various materials within the multilayered geometry.
• * Presents expressions for Green's functions for isotropic, anisotropic solids, and fluid media.

Main Results:

• * Successfully models elastic wave propagation in complex multilayered structures generated by finite-size transducers.
• * The formulation accommodates general anisotropy and irregularities at interfaces.
• * Computed results are validated through stress and displacement continuity checks at interfaces and comparison with flat plate models.

Conclusions:

• * The proposed semianalytical method offers a rigorous and versatile tool for analyzing ultrasonic fields in multilayered anisotropic and isotropic solids.
• * This method overcomes limitations of traditional approximate techniques, enabling more accurate simulations.
• * The findings are significant for non-destructive testing and structural health monitoring applications in various engineering fields.